Finite-element impact response of debonded composite turbine blades

2014 ◽  
Vol 03 (01) ◽  
pp. 1450001
Author(s):  
Sudip Dey ◽  
Amit Karmakar
Keyword(s):  
Finite Element ◽  
Dynamic Equilibrium ◽  
Turbine Blades ◽  
Hertzian Contact ◽  
Integration Scheme ◽  
Element Formulation ◽  
Normal Impact ◽  
Low Velocity ◽  
Conical Shells ◽  
The Impact

This paper investigates on the transient behavior of debonded composite pretwisted rotating shallow conical shells which could be idealized as turbine blades subjected to low velocity normal impact using finite-element method. Lagrange's equation of motion is used to derive the dynamic equilibrium equation and the moderate rotational speeds are considered neglecting the Coriolis effect. An eight-noded isoparametric plate bending element is employed in the finite element formulation incorporating rotary inertia and effects of transverse shear deformation based on Mindlin's theory. The modified Hertzian contact law which accounts for permanent indentation is utilized to compute the impact parameters. The time-dependent equations are solved by using Newmark's time integration scheme. Parametric studies are performed to investigate the effects of triggering parameters like angle of twist, rotational speed, laminate configuration and location of debonding considering low velocity normal impact at the center of eight-layered graphite-epoxy composite cantilevered conical shells with bending stiff [Formula: see text], torsion stiff ([45°/-45°/-45°/45°]s) and cross-ply ([0°/90°/0°/90°]s) laminate configurations.

Finite Element Transient Dynamic Analysis of Delaminated Composite Conical Shells Subject to Low Velocity Impact

2012 ◽  
Author(s):  
Sudip Dey ◽  
Manoj Roy ◽  
Amit Karmakar
Keyword(s):  
Finite Element ◽  
Dynamic Equilibrium ◽  
Hertzian Contact ◽  
Low Velocity Impact ◽  
Element Formulation ◽  
Low Velocity ◽  
Transient Dynamic Analysis ◽  
Integration Algorithm ◽  
Conical Shells ◽  
Transient Dynamic

This paper investigates on the transient dynamic response of delaminated composite pretwisted shallow conical shells subjected to low velocity normal impact. Turbomachinery blades with low aspect ratio could be idealized as twisted rotating cantilever composite conical shells. To derive the dynamic equilibrium equation, Lagrange’s equation of motion is used for moderate rotational speeds neglecting the Coriolis effect. An eight noded isoparametric plate bending element is employed in the finite element formulation incorporating rotary inertia and effects of transverse shear deformation based on Mindlin’s theory. To satisfy the compatibility of deformation and equilibrium of resultant forces and moments at the delamination crack front a multipoint constraint algorithm is incorporated which leads to unsymmetric stiffness matrices. The modified Hertzian contact law which accounts for permanent indentation is utilized to compute the contact force, and the time dependent equations are solved by Newmark’s time integration algorithm. Parametric studies are conducted in respect of triggering parameters like location of delamination, angle of twist and velocity of impactor for the centrally impacted graphite-epoxy torsion stiff composite conical shells.

scholarly journals Transient Dynamic Response of Delaminated Composite Rotating Shallow Shells Subjected to Impact

2006 ◽  
Vol 13 (6) ◽  
pp. 619-628 ◽  
Author(s):  
Amit Karmakar ◽  
Kikuo Kishimoto
Keyword(s):  
Finite Element ◽  
Dynamic Equilibrium ◽  
Time Integration ◽  
Hertzian Contact ◽  
Element Formulation ◽  
Low Velocity ◽  
Element Analysis ◽  
Integration Algorithm ◽  
Shallow Shells ◽  
Transient Dynamic

In this paper a transient dynamic finite element analysis is presented to study the response of delaminated composite pretwisted rotating shallow shells subjected to low velocity normal impact. Lagrange's equation of motion is used to derive the dynamic equilibrium equation and moderate rotational speeds are considered wherein the Coriolis effect is negligible. An eight noded isoparametric plate bending element is employed in the finite element formulation incorporating rotary inertia and effects of transverse shear deformation based on Mindlin's theory. To satisfy the compatibility of deformation and equilibrium of resultant forces and moments at the delamination crack front a multipoint constraint algorithm is incorporated which leads to unsymmetric stiffness matrices. The modified Hertzian contact law which accounts for permanent indentation is utilized to compute the contact force, and the time dependent equations are solved by Newmark's time integration algorithm. Parametric studies are performed in respect of location of delamination, angle of twist and rotational speed for centrally impacted graphite-epoxy composite cylindrical shells.

Effect of oblique angle on low velocity impact response of delaminated composite conical shells

2014 ◽  
Vol 228 (15) ◽  
pp. 2663-2677 ◽  
Author(s):  
Sudip Dey ◽  
Amit Karmakar
Keyword(s):  
Time Integration ◽  
Impact Angle ◽  
Oblique Impact ◽  
Dynamic Responses ◽  
Hertzian Contact ◽  
Low Velocity Impact ◽  
Integration Scheme ◽  
Element Formulation ◽  
Low Velocity ◽  
Conical Shells

This paper presents the effect of oblique impact angle on low velocity transient dynamic responses of delaminated composite pretwisted shallow conical shells. An eight-noded isoparametric quadratic plate bending element is employed in the finite element formulation incorporating rotary inertia and effects of transverse shear deformation based on Mindlin’s theory. The modified Hertzian contact law which accounts for permanent indentation is utilized to compute the contact force, and the time-dependent equations are solved by Newmark’s time integration scheme. A comparative study is carried out on torsion stiff, cross-ply, and bending stiff laminates to investigate the effects of triggering parameters like angle of twist, plate displacement, striker’s velocity, and displacement for graphite-epoxy composite laminate subjected to low velocity oblique impact at the center.

Transient Dynamic Response of Delaminated Composite Twisted Cylindrical Shells Subjected to Low Velocity Impact

2005 ◽  
Vol 297-300 ◽  
pp. 1285-1290 ◽  
Author(s):  
Amit Karmakar ◽  
Kikuo Kishimoto
Keyword(s):  
Finite Element ◽  
Cylindrical Shells ◽  
Relative Size ◽  
Hertzian Contact ◽  
Low Velocity Impact ◽  
Element Formulation ◽  
Low Velocity ◽  
Element Analysis ◽  
Integration Algorithm ◽  
Transient Dynamic

In this paper a transient dynamic finite element analysis is presented to study the response of centrally impacted delaminated composite pretwisted cylindrical shells. An eight noded isoparametric plate bending element is employed in the finite element formulation. Effects of transverse shear deformation and rotary inertia are included. To satisfy the compatibility of deformation and equilibrium of resultant forces and moments at the delamination crack front a multipoint constraint algorithm is incorporated. The modified Hertzian contact law which accounts for permanent indentation is utilized to compute the contact force, and the time dependent equations are solved by Newmark’s time integration algorithm. Parametric studies are performed in respect of relative size of delamination and angle of twist for graphite-epoxy composite cylindrical shallow shells subjected to low velocity normal impact.

Time Dependent Low Velocity Impact Response of Turbomachinery Blade Made of Porous Exponential FGM

2019 ◽  
Author(s):  
Apurba Das ◽  
Gopal Agarwal ◽  
Kazuaki Inaba ◽  
Amit Karmakar
Keyword(s):  
Contact Force ◽  
Conical Shell ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Integration Scheme ◽  
Low Velocity ◽  
Conical Shells ◽  
Velocity Impact ◽  
Multiple Impact ◽  
The Impact

Abstract This study presents transient dynamic response of porous and non-porous exponential functionally graded (E-FGM) conical shells subjected to low velocity single and multiple impact. Hertzian contact law in modified form considering permanent indentation is used to calculate the impact response parameters. For finite element formulation eight-noded isoparametric shell element having five degrees of freedom per node is used. The dynamic equations for the low velocity impact problems are solved by Newmark’s time integration scheme. Parametric studies in terms of contact force, initial velocity of impactor, impactor displacement and shell displacement for Stainless Steel-Silicon Nitrite porous and non-porous conical shells (idealized as rotating turbo-machinery blade) under low velocity single and multiple impact are analyzed. Twist angle has significant effect on contact force but has marginal effect on contact duration. Contact force for perfect (porosity free) case is higher than that of porous one and the contact forces are found to decrease with higher porosity factor. Even porous FG conical shell is predicting lower contact force and higher shell displacement than that of uneven porous FG conical shell for a given porosity factor.

Geometrically nonlinear static and dynamic analysis of CNT reinforced laminated composite plates: A finite element study

2021 ◽  
pp. 095440622110089
Author(s):  
Balakrishna Adhikari ◽  
BN Singh
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Dynamic Response ◽  
Integration Scheme ◽  
Static And Dynamic Analysis ◽  
Finite Element Study ◽  
Nonlinear Eigenvalues ◽  
Nonlinear Static ◽  
The Impact ◽  
Element Study

In this paper, a finite element study is conducted using the Green Lagrange strain field based on vonKarman assumptions for the geometric nonlinear static and dynamic response of the laminated functionally graded CNT reinforced (FG-CNTRC) composite plate. The governing equations for determining the nonlinear static and dynamic behavior of the FG-CNTRC plate are derived using the Lagrange equation of motion based on Reddy's higher order theory. Using the direct iteration technique, the nonlinear eigenvalues for analyzing the free vibration response are obtained and the nonlinear dynamic responses of the FG-CNTRC plate are encapsulated based on the nonlinear Newmark integration scheme. The impact of the amplitude of vibration on mode switching phenomena and the consequence of the duration of the pulse on the free vibration regime of the plate are outlined. Also, the effect of time dependent loads is studied on the normal stresses of the plate. Furthermore, the impact on the nonlinear static and dynamic response of the laminated FG-CNTRC plate of various parameters such as span-thickness ratio (b/h ratio), aspect ratio (a/b ratio), different edge constraints, CNT fiber gradation, etc. are also studied.

Response of Mild Steel Pipes Under High Mass Low Velocity Impacts

2014 ◽  
Author(s):  
Shamsoon Fareed ◽  
Ian May
Keyword(s):  
Finite Element ◽  
Mild Steel ◽  
Impact Energy ◽  
High Mass ◽  
Low Velocity ◽  
Element Analysis ◽  
Steel Pipes ◽  
Impact Tests ◽  
The Finite Element Analysis ◽  
The Impact

Accidental loads, for example, due to heavy dropped objects, impact from the trawl gear and anchors of fishing vessels can cause damage to pipelines on the sea bed. The amount of damage will depend on the impact energy. The indentation will be localized at the contact area of the pipe and the impacting object, however, an understanding of the extent of the damage due to an impact is required so that if one should occur in practice an assessment can be made to determine if remedial action needs to be taken to ensure that the pipeline is still serviceable. There are a number of parameters, including the pipe cross section and impact energy, which influence the impact behaviour of a pipe. This paper describes the response, and assesses the damage, of mild steel pipes under high mass low velocity impacts. For this purpose full scale impacts tests were carried out on mild steel pipe having diameter of 457 mm, thickness of 25.4 mm and length of 2000 mm. The pipe was restrained along the base and a 2 tonnes mass with sharp impactor having a vertical downward velocity of 3870 mm/sec was used to impact the pipe transversely with an impact energy of 16 kJ. It was found from the impact tests that a smooth indentation was produced in the pipe. The impact tests were then used for validation of the non-linear dynamic implicit analyses using the finite element analysis software ABAQUS. Deformations at the impact zone, the rebound velocity, etc, recorded in the tests and the results of the finite element analysis were found to be in good agreement. The impact tests and finite element analyses described in this paper will help to improve the understanding of the response of steel pipes under impact loading and can be used as a benchmark for further finite element modelling of impacts on pipes.

scholarly journals Particle Finite Element Simulation of Chip Formation in Cutting Processes

2017 ◽  
Vol 869 ◽  
pp. 50-61
Author(s):  
Matthias Sabel ◽  
Christian Sator ◽  
Ralf Müller ◽  
Benjamin Kirsch
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Large Deformations ◽  
Element Formulation ◽  
Particle Finite Element Method ◽  
Element Simulation ◽  
Modeling Techniques ◽  
Cutting Processes ◽  
The Impact ◽  
Cutting Simulations

The formation of chips in cutting processes is characterised by large deformations and large configurational changes and therefore challenges established modeling techniques. To overcome these difficulties, the particle finite element method (PFEM) combines the benefits of discrete modeling techniques with methods based on continuum mechanics. In this work an outline of the PFEM, as well as an explanation of the finite element formulation are provided. The impact of the boundary detection on the structural integrity is studied. The numerical examples include a tensile test as well as cutting simulations. The paper is concluded by a comparison of cutting forces with analytical results.

The Finite Element Analysis of Dynamic Interaction of High-Speed Shinkansen, the Rail, and Bridge

1993 ◽  
Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Nobuyuki Matsumoto
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
High Speed ◽  
Response Analysis ◽  
Element Formulation ◽  
Element Analysis ◽  
Finite Element Program ◽  
The Finite Element Analysis ◽  
Element Program ◽  
The Impact

Abstract A finite element formulation to solve the dynamic behavior of high-speed Shinkansen cars, rail, and bridge is given. A mechanical model to express the interaction between wheel and rail is described, in which the impact of the rail on the flange of wheel is also considered. The bridge is modeled by using various finite elements such as shell, beam, solid, spring, and mass. The equations of motions of bridge and Shinkansen cars are solved under the constitutive and constraint equations to express the interaction between rail and wheel. Numerical method based on a modal transformation to get the dynamic response effectively is discussed. A finite element program for the dynamic response analysis of Shinkansen cars, rail, and bridge at the high-speed running has been developed. Numerical examples are also demonstrated.

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